Tube-forming mill



rch '29 1927. Ma R. c. STIEFEL TUBE FORMING MILL Filed April 5, 1926 IIlm 4 Sheets-Sheet l F'LBJ.

l WT/VESLSES March r29, 1927 R, C, sTlEr-'EL TUBE FORMING MILL FiledApril 5, 1926 4 Sheets-Sheet 2 FIE.Z..

mandi? 1** Zmfllw 1927. 1,622,744 March 29 R. c. STIEFEL TUBE FORMINGMILL Fild April '5, 1926 4 sheets-sheet s 1927. 1,622,744 March 29 R. c.STIEFEL TUBE FORMING MILL Filed April 5, 1926 4 Sheets-Sheet 4 FIELE.

Aam,

laccata! Mm. 29, '1921.

man c. s'rmrnr., or nL'Lwoon ein, PENNSYLVANIA.

Tuna-.romaine .appiieatian'aiednprn 5, 192s. serial ma 99,7%?.

The invention relates to the generaly type of tube-forming .mills inwhich a heated piercedbillet or' other tubular blank is in--termittently acted .upon increment-by-increment to elongate it andreduce its wall thickness, the blank bein mounted upon a mandrel whichis intermittently moved into andy through the mill to present successiveincrements of the blank to the action ofthe mill, and the invention hasparticularly to do with mills of this Atype in which successiveincrements of a blank are acted upon by a series of uniformly groovedrolls which have orbital movements about central axes.-

The object of the invention is to improve the construction and operationof mills of the type described.

The invention is illustrated in the accompanying drawings, ofwhich Fig.1 is a vertical central sectional view through a mill in the 'plane ofits workin@r pass, this plane being indicated bythe ine I-l, Fig. 2;Fig.` 2 a vertical central sectional' view of the mill taken at rightangles to Fig. 1, the

lane of view being indicated by -the line li-II, Fig. 1; Fig. 3 a detailvertical sectional view-taken on the-line III-Ill, Fig. 2; Fi i a detailsectional vievvtaken on the line l -IV, Fig. 3; Fig. 5 a horizontalsectional view taken on the line V--V, Fig. 2;

and Fig. 6 a view corresponding to Fig. 5 illustrating a modication ofthe mounting of tube-forming rolls.

The mill provided according to this invention comprises a pair of drivenshafts rotatably mounted in a suitable housing, around each of whichthere is arranged a series of grooved forming rolls held in spacedvrelation to each other. Each of the several grooved rolls forming thisseries has p a peripheral portion in bearing contact with a cylindricalface of the shaft around which the rolls are disposed, the arrangementbeing such that the shafts'rotate the grooved rolls in ka manner similarto the actionA of a planetary gear. Provision is made for causing thetwo series of grooved rolls to move at uniform angular rates about theaxes of the shafts upon which they bear so .that the rolls forming thetwo series cooperate in pairs to act upon successive increments of atubular blank. The mill is intended to be used in coordination with asuitable feeding mechanism adapted tol intermittently advance a mandreland its supported blank between the functioning of each pair of groovedrolls to 'present successive increments *y ofthe blank to the successivepairs of actin`g rolls, the feeding Amechamsm bein also adapted torotate the blank on its longitudinal axis through anl angle of 90between the action of successive pairs of grooved rolls, this turningbeing el.'-

fected at the saine time the blank is moved forwardly. Because suchblank-feeding mechanism iswell known in this art, and because variousforms of it may be used in coordination with the' mill providedaccording tothis invention, no such feeding mechanism is illustrated inthe drawings.

Having reference now to the illustrative embodiment of the invention, apair of shafts indicated as a whole by the letters A and B are suitablysupported by a housing 1, the lower shaft B preferably having noprovision for vertical movement, and the upper shaft A being mounted fora limited vertical movement, the extent of which may be determined byscrews 2. Since beth of these shafts are preferably constructed alike..and are so shown in the drawings, the explanation of their constructionwill be limited to a description of shaft A. Adjacent to its ends it isprovided with bearing portions 3 which' are rotatably mounted on bearingblocks 4, andat its ends it is provided with angular portions 5 forconnection to wahble'rs or other suitable drives. Adjacent to bearingportions 3, this shaft is provided with shoulders 6 surrounding whichthere is a cage 7 for supporting the ends of a series of groovedtube-forming rolls 8, the cage being rotatable upon the shoulders, but,for a reason presently to be explained, preferably having frictionbearing contact with the shoulders. The central portion 9 of shaft A iscylindrical and affords a bearing for peripheral portions of the groovedrolls.

As shown in Fig. 4, cage 7 may comprise a ipair of rings 10, onesurrounding each of =the shoulders 6 of shaftA, each of which ringsisprovided with al series of inwardly extending arms l5 arranged betweenrolls 8 and meetin grooved ro ls in bearing blocks 1.9 supported formovements radially of shaft A in suitable radially disposed pocketsformed on the inner or a jacent faces of the rings 10 of cage 7.

Provision is made for continuously holding the eripheral bearingportions of 8 in contact with the cylindrical portions 9 of shaft A. Tosuch end, the peripheries of cage rings 10 are preferably provided witha plurality of arc-shaped springs 25 each having its ends yieldinglybearing upon the outer faces of an adjacent pair of bearing blocks 19 tourge them toward shaft A. These s rings may be attached to cage 7 bysuita le bolts26. Provision is also made for causing cage 7 to rotatewith shaft A at such times as the grooved rolls may not be acting upon abla-nk. This may be done in whole or in part by the frictional contactof the inner bearing Surfaces of caffe rings 10 upon shaft shoulders 6.In addition to this, friction rings 27 may be arranged between the innerfaces of cage rings 10 and off-set portions of shaft A, the frictionrings being provided with projections 28 which engage the cage rings.These friction rings are yieldingly pressed into engagement with shaft Aby means of a plurality of springs 29 so that additional force isapplied to cause the cage to rotate with the shaft when pairs of rolls 8are not in engagement with a blank.

Surrounding shaft B there is a ca e 7 which supports a series of groovedrol s 8, the construction and arrangement of this cage and rollers beingthe same as the corresponding parts surrounding shaft A. To the end thatthe several rolls 8 and 8 forming the two Series may be brought intotubeforming positions in pairs, cages 7 and 7a are caused to move atuniform angular rates about the axis of their contained shafts byproviding the peripheries of these cages with intermeshing teeth 30 and308.

In the embodiment of the invention illustrated in Figs. 1-5 formingrolls 8 and 8 are arranged with their axes parallel to each other and tothe axes of shafts A and B. If de iied, the forming rolls may be mountedto form pairs of cross-rolls. In other words, they may be so supportedin their cages that their axes cross each other when they meet in pairsin tube-forming or reducing positions. To this end, as shown in Fig. 6,rolls 35 surrounding shaft A may have their trunnions 36 mounted inoblique openings 37 in bearing blocks 38 supported by a cage 39, and thesecond series of rolls 40 surrounding shaft B may be similarly mountedin a cage 41, the axes of the rolls crossing each other as shown. By somounting the two series of forming rolls, a tubular blank being actedupon by the rolls is turned on its longitudinal axis by the cross rollaction of the rolls.`

In the operation of the mill, having reference particularly to theembodiment of the invention illustrated in Figs. 1-5, a tubular blank 45is supported upon a mandrel rod 46, which, by any suitable form offeeding mechanism, is intermittently advanced to present successiveincrements of the blank to the action of cooperating pairs of formingrolls 8 and 8, and is turned on its longitudinal axis through an angleof between the operation of each-pair of forming rolls. Shafts A and Bare suitably driven in the directions indicated in Fig. 1 by the arrowsplaced on these shafts with the result that rolls 8 and 8a are caused toroll upon blank 45 in the directions indicated 'by the arrows on thepair of these rolls shown in Fig. 1 as being in contact with the blank.The rotation of the successive pairs of cooperating rolls 8 and 8ncauses the cages to rotate in the same directions as shafts A and B, asis indicated by the arrows extending through the rolls'8 and 8a shown inFi l as being in contact with the blank. T e intermittent rolling actionof the pairs of rolls 8 and 8 serves to reduce the wall thickness of theblank and to elongate it as generall indicated. Pressure 1s im arted tothe lank through the forming rol by the peripheral bearing of the forminrolls upon shafts A and B which hold t e formin rolls in definite spacedrelationship to eac other so that the reduction and elongation of theblank is uniform throughout. During the interval elapsing between theoperation of successive series of forming rolls, cages 7 and 7a arerotated to present a succeeding pair of forming rolls to the blank bothb the friction of cage rings 10 on shaft sho ders 6 and by the frictiondrive imparted to the cages by the shafts through friction rings 27.After the tube has been reduced and elongated, such irregularities asmay appear on its outer surface, and as usually appear on tubes formedby mills of this type, may be removed in the well known manner bypassing the tube through a reeling mill.

According to tlie'provisions of the patent statutes, I have explainedthe principle and operation of my invention, and have illustrated anddescribed what I now consider to represent its best embodiment. However,I desire to have it understood that, within the scope of the appendedclaims, the invention may be practiced by other forms of.

mills than that particularly illustrated and described.-

I claim as my invention:

1. A seamless tube-forming mill, comprising a pair of rotary shafts, aseries of grooved forming rolls held in spaced relation to each otheraround and having preipheral ortions in bearing contact with a cylinrical face of each of said shafts for imparting rotation to the rolls,and means for causing said two series of rolls to continuously move atuniform angular `rates about the axes of the shafts upon which they bbear.

2. A seamless tube-forming mill, comprising a pair of driven rotaryshafts, a rollsupporting cage mounted for rotation upon each shaft, aseries of rotatably mounted in each cage in spaced relation to eachother, and having peripheral portions in bearing contact with acylindrical face of the shaft Within the cage, and means for causing thecages to continuously move at uniform angular rates about the axes oftheir respective supporting shafts.

3. A seamless tube-forming mill, comprising a pair of driven rotaryshafts, a rollsupporting cage mounted for rotation upon each shaft, aseries of grooved forming rolls rotatably mounted in each cage in spacedrelation to each other, yielding means for grooved forming rolls tooperate in pairs' holding peripheral ortions of said rolls in earingcontact Wit a cylindrical face of the shaft Within the cage, and meansfor causing the cages tocontinuously move at uniform angular rates aboutthe axes of their respective su porting shafts.

4. A seamless tu -formingI mill, comprising a pair of driven rotaryshafts, a rollsupporting cage mounted for rotation upon each shaft, aseries of grooved forming rolls rotatably mounted in bearings arrangedin each cage for movements radially; of its contained shaft, meansacting through said bearings for holding peripheral portions of saidrolls in bearing Contact With a cylindrical face of said shaft Withinthe cage, and means for causing the cages to continuously move atuniform angular rates about the axes of their respective supportingshafts. In testimony whereof, I sign my name.

RALPH C. STlEFEL.

